Nozzle exit valve



3 Sheets-Sheet l Filed April 27, 1953 N9. @.N E @w mw mm t om,

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NozzLE EXIT VALVE Filed April 27, 1953 s sheets-sheet 2 Z s Z f //54 3lI1 l 3l 50 /4 30 :fig #(95 INVENTOR. 10H/v E CAMPBELL.

June 18, 1957 J. F. CAMPBELL NOZZLE EXIT VALVE Filed April 27, 1953 3Sheets-Shea?l 3 JNVENToR.

/0/-N E CAMPBELL United `States Patent O NOZZLE EXIT VALVE `lohn F.Campbell, Euclid, Ohio Application April 27, 1953, Serial No. 351,287

6 Claims. (Cl. 299-107.6)

This invention relates as indicated to a nozzle exit valve, and moreparticularly to a particular ty-pe of nozzle valve especially adaptedfor use in spray nozzles of the type disclosed in my co-pendingapplications Serial No. 105,975, filed July 21, 1949, now Patent No.2,656,- 218, and Serial No. 333,569, led January 27, 1953, now Patent2,749,182, of which this application is a continuation-in-part.

Reference may be had to said co-pending applications for a more detailedexplanation of certain of the problems involved in the design of spraynozzles for use in internal combustion engines and especially jetengines, and also for a more detailed explanation of the manner in whichuid may be conducted to the exit orifice of the nozzle to obtain thedesired effects. p

There are at present several different types of engines employing liquidfuels which require to be injected into the combustion chambers of thesame, such engines including the well-known automotive internalcombustion engine, diesels, the turbo-jet, prop-jet, and ram-jet enginesand the like. While such latter types of engines are at present largelyemployed in aircraft, it is expected that they will shortly findapplication in railway locomotives and ships. In certain-of such enginesit is necessary to provide for a wide range of fuel ow between selectedminimum and maximum limits while at the same time maintaining a lowover-al1 pressure drop through the nozzle between the fuel intakemanifold and the combustion chamber.

Open orifice type nozzles have been employed in the past in suchapplications but without any great measure of success, principallybecause of their limited ow range of approximately l to 1. The ow rangewhich must be obtainable for continuously efficient operation of certainof the more modern jet engines is in some cases as much as 125 to 1. Theusual open orifice nozzles are not capable of any such range ofperformance since in such nozzles when the rate of flow is increased bya stated factor the corresponding line pressure will require to beincreased approximately by such factor squared. To attempt to providefor any great range of flow with this latter type of nozzle is thereforewholly impracticable as leading to impossibly high line pressures in theupper range of flow.

With closed and/or variable orifice nozzles I have,

however, found it possible to obtain a wide range of flow withoutexcessive intake pressures being required to achieve high ow rates. Aserious diiculty with this latter type of nozzle, however, isencountered in attempting to meet the rigid specifications generallyimposed as to maintenance of a designated angle of spray cone at alloperating rates of flow. When the rate of flow drops v to conform to adesignated predetermined pattern, and this has likewise been found verydifficult to achieve.

As explained in my aforesaid co-pending applications, I have developed anovel form of nozzle which has proved to be highly efcient and to affordthe desired characteristics over a wide range of ow. v

It is usually desirable to maintain the spray envelope produced by thenozzle at a substantially constant angle over such large ow range. Ifthevalve orifice and the exit valve member cooperating therewith areprovided with opposed seat portions to afford a particular Vangle to thespray envelope, it is found that at high rates of flow the fuel envelopedischarged from the orifice will assume a rounded or umbrella shapeinstead of holding to the desired conical form as obtained at low fuelflow. The general result of this effect is equivalent to reducing theangle of the conical fuel envelope, and such change of angle is nottolerated by present-day engine specifications.

It is accordingly a principal object of my invention to provide a novelform of nozzle exit valve and particularly of the exit valve memberitself which will automatically produce the desired form of spraypattern or envelope at the various different rates of flow, with theexit valve member being adjusted accordingly axially of the exitorifice.

Other objects will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention`then comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawing setting forth in detail certain illustrativeembodiments of the invention, these being indicative, however, of but afew of the various ways in which the principle of the invention may beemployed.

In said annexed drawing:

Fig. l is a longitudinal sectional view of one embodiment of my newnozzle as shown and described in'my aforesaid application Serial No.333,569 and showing the manner of mounting the exit valve member and itsrelationship to the swirl chamber immediately upstream of the exitorice;

Fig. 2 is an enlarged view in cross-section of the exit end of thenozzle illustrating one contour of my new exit valve member;

Fig. 3 is a View similar to Fig. 2 but showing the exit valve membershifted to a more open position and not sectioned;

Fig. 4 shows a modified form of exit valve member;

Fig. 5 shows such exit valve member shifted for further opening of thevalve;

Fig. 6 shows another form of exit valve member;

Fig. 7 illustrates the manner in which an annular or circumferentialvent may be provided in my new exit valve member for venting theinterior of the nozzle into the spray envelope; and

Figs. 8 and 9 illustrate yet another form of my new exit valve member.

Referring now more particularly to Fig. 1 of the drawing, the embodimentof my invention there illustrated comprises an outer nozzle body 1 ofgeneral cylindrical form having an enlarged base portion 2 adapted tobel lar recess 8 opposed to a corresponding annular recess 9 formed inthe outer body member 1 and the inner liner member 10 press ttedtherein. An annular filter 11 ywhichmay be of 'asbestosvfiben forexampleheld between layers'oftilter cloth 12 and 13 is'interposed between suchannular recesses .8 and `9 and firmly clamped between kmembers 1 and 3so that fuel or other liquid entering recess 8 through passage 7 canreach annular cavity 9 only through such filter.

The other end of the nozzle body is closed except for an axiallydisposed exit orifice 14. All parts of the vnozzle may desirably be ofstainless steel, for example.

As above indicated, the inner liner member is press fitted withincylindrical nozzle body 1, such liner being 'provided with a pluralityof longitudinally extending grooves in its outer surface adapted to formchannels or 4passages in conjunction with the inner cylindrical wall 15of nozzle body 1. Liner 10 is likewise of cylindrical shape, its innerperiphery 16 defining the axial bore within which valve member 17 isadapted to slide. In the embodiment illustrated, ten equally spacedgrooves 18 are provided in the outer periphery of member 10 opening tothe end of such member toward exit orifice 14 but closed at their otherends. Five somewhat smaller' Agrooves (not shown) are similarly formedin the outer periphery of liner 10 intermediate every other pair of suchgrooves 18 but such additional grooves do not extend quite to either endof liner 10. Instead, generally radial passages lead therefrom directlyto the inner bore 16 of the liner at a point to the left of the valvemember 17 so that such latter passages are always in communication withintakepassage 6.

For convenient manufacture and assembly, a separate .annularfmember 22is fitted over end liange 23 of liner 1l),

being interposed therebetween and the outer end 24 of the nozzle body.As shown, such member is thereby spaced from the inner cylindrical wallof nozzle body 1 and is formed with a plurality of tangential slots 2Sopening into a swirl chamber 26 immediately upstream of nozzle Yexitorifice 14. Accordingly, fiuid admitted to channels 18 by reciprocationof valve member 17 is caused to enter chamber 26 through such diagonalslots .25 in communication therewith, imparting an accelerat- .channels(not shown) which communicate directly with bore 16 and inlet passage 6to the left of valve member 17 lead to such annular chamber 28 so thateven when valve member 17 has not been reciprocated to admit fluid fromintake passage 6 to channels 18, iuid may flow through such otherchannels to annular channel 28 and small helical grooves 29 leading toswirl chamber 26.

vvValve member 17 comprises a cylindrical shell closed toward the fuelinlet end of the nozzle but open toward member 27. Such valve memberfits closely within bore 16 of liner 10 for axial reciprocationtherewithin.

Exit valve member 3f) extends through exit orifice 14 and is providedwith a radially outwardly fiaring flange 31 adapted to engage and seatagainst the outer edge of such orice. An inner stem 32 fits closely foraxial reciprocation within a central bore in member 27 Slide valvemember 17 and poppet valve member 36 are interconnected for movementtogether by means of a rod 33 (a fine spring wire, which in one case hada diameter of .014 inch) which extends through tubular valve stem 32 andis secured as'by brazing at its Aouter end to aplug 34 in the outwardlyprotruding portion of exit valve member 30. Such tubular stem '32 isopen Aatits 4 inner end to the interior of bore 16 of liner 10 and atits outer end communicates with a small chamber within valve member 30having small exit orifices such as 35 leading to the exterior of thenozzle. The other end of rod 33 is secured to an adjusting screw 36threaded within the end of valve member 17, the protruding end of screw36 being engaged and enclosedby a lock nut 37. A cornpression spring 38is seated at one end against a washer 39 bearing against the end ofvalve member 17 and at the other end bears against inner plug 27. Itwill thus be seen that by turning screw 36 valve member 17 may be drawntoward plug 27 with attendant further compression of spring 38 and moreforceful seating of poppet valve member 30.

Steel rod 33, although slender, is straight and therefore capable ofcausing both valve members 17 and 30 to reciprocate in unison. Such rodis, however, flexible to permit a slight degree o'fmisalignment of suchtwo valve members without tending to cause the latter to bind. It isimportant in nozzles of this type that they be quite sensitive andresponsive to changes in fluid pressure. By securing the ends of rod 33in adjusting screw 36 and the extreme outerendiof valve member 3f)respectively as by low temperature brazing, a relatively long rod may beemployed facilitating such slight deflection as may be required of thesame. It may be kept invmind that frequently nozzles of the type hereunder consideration are only an inch or so long, and the various movingparts are accordingly on a very small scale. As well shown in Fig. l,adequate lateral clearance is provided for rod 33 to permit suchdeflection of the same. Compression spring 38 may desirably be formedfrom a length of tubing slotted by two helical slots terminating atdiametrically opposite points in the annular end portions thereof. Aspring thus formed is adapted to transmit pressure directly axiallywithout canting. Any tendency of valve member 17 to'bind on this accountis accordingly avoided.

As also shown in Fig. l, lanother longitudinally extending -channel isprovided `formed 'by grooves 40 and 41 in the outer periphery of liner10, groove 40 communicating with annular passage 9 through'constrictedrelief 42 and communicating with groove 41 through a similar relief 43.Consequently, filtered fluid willbe conducted through. transversepassages 44, 45 and 46 to the sliding fits of valve member 17 and valvestern 32. Contaminated fluid which has not been filtered but enters thenozzle directly through inlet passage 6 is thereby prevented fromentering into such 'sliding fits since the filtered fiuid will be atsomewhat higher lpressure (there is, of course, a

.considerable pressure drop from passage 6 to annular `particles whichmay under some circumstances become interposed between the relativelysliding surfaces and which would tend to reduce the sensitivity of thedevice. Only filtered uid reaches the interior of valve member '17. Itwill be seen that the operation of this anti-clogging `means is whollyautomatic and requires no maintenance other than very occasionalcleaning or replacement of filter 11. Since the fluidtiow through suchfilter is very slow, a long period will elapse before the filter willbecome clogged. Moreover, thenozzle considered as a Vwhole is nowenabled to accommodate itself to contaminated fuels Without any specialtreatment of the latter passing therethrough and without any consequentreduction in flow.

Further details and modifications of the above-described nozzleconstruction are set forth more fully in my copending application SerialN0. 333,569 referred to above.

As previously indicated, the `present invention is more particularlyconcerned with the construction and operation ofthe exit valvememberI30, several embodiments of'which are illustrated 'inFigs' 2-9 ofthe drawing. Re-

ferring initially to the Figs. 2 and 3 form, it will be Vseen that theshoulder or peripheral ange 31 has a bevelled inner surface 48 adaptedto seat and close exit orifice 14 and also, when Valve stem 32 has beenonly slightly reciprocated to the right as viewed in Fig. 2 to open thepoppet valve but slightly, to direct the spray cone S at a rather large'angle, whereas when such valve stem 32 is shifted further to open thevalve as shown in Fig. 3 the angle of the spray cone S is now determinedby the more acute angle of conical surface 49 which is separated fromthe more obtusely conical surface 48 by an intervening generallycylindrical land 50. Such land causes the uid to break away from thevalve member at the point where such land interrupts the conical surface49 and the latte'r accordingly controls the angle of the spray cone athigher rates of flow.

Valve stem 32 is necked down at 51 where it extends through swirllchamber 26, and it has been found that the iluid swirling rapidlyaround such stem portion 51 tends to adhere thereto as it passes throughthe exit orifice 14. It is accordingly ordinarily important that a landsuch as land 50 or a similar interruption be provided to break the fluidaway from the surface of the valve member to form the spray cone S.Different jet engine kspecifications call for different spray coneangles at various rates of flow, sometimes smaller at high rates of llowand sometimes vice versa. Control-of the form of spray envelope may beachieved in accordance with my invention by proper selection of theconical surfaces such as 48 and 49.

Figures 4 and 5 illustrate a modification of my invention similar to theFigs. 2 and 3 embodiment but with conical valve surfaces 52 and 53selected to aiord a spray cone of relatively small angle when the valveis only slightly open as shown in Fig. 4 and a spray cone ofconsiderably larger angle when the valve is relatively widely opened asshown in Fig. 5. In the former instance, the fluid escapes from the exitvalve orifice where'the latter is opposed to conical surface 53 whereasin the latter instance it escapes where conical surface 52 is adjacentthe valve orifice 14. The cylindrical flat 54 provides a break betweensuch two conical surfaces whereby the swirling uid is caused to breakaway from the valve member into the spray cone S.

Now referring to Fig. 6 of the drawing, I show a valve member in whichthe conical surfaces 55 and 56 are of substantially equal angle althoughseparated by the intervening cylindrical at 57. Such flat serves toprovide a more constricted annular orifice for the escaping fluid whenthe valve is only slightly opened as shown in Fig. 6, and when the valvemember has been reciprocated considerably further to the right, conicalsurfaces 55 will then control the angle of the spray cone. -It is thuspossible to obtain a spray cone of substantially uniform anglethroughout the opening and closing movement of the exit valve member atdifferent rates of flow.

The Fig. 7 embodiment is somewhat similar to the Figs. 2 and 3embodiment in that the spray cone' is at a somewhat wider angle when thevalve is initially opened than later when such valve is widely opened.Instead of providing openings such as 35 (Fig. 1) for escape of ventedfluid, however, an annular opening 58 is provided in the inner face ofthe conical valve surface initially determining the angle of the spraycone. The' vented lluid accordingly is discharged directly into suchspray cone for incorporation therein without substantially modifying thecharacteristics of the same.

It will be seen therefore that the spray cone or sheaf is formed by theouter or primary cone for small amounts of valve opening and by the'inner or secondary cone for large amounts of valve opening. Forintermediate degrees of opening, the spray cone angle is formed by fluidblending between the primary and secondary conical surfaces. Such blendpoint is selective' relative to the amount of valve opening by properselection of the diameter and length of the intermediate cylindricalportion.

In Figs. 8 and 9' of the drawing it will be noted that the nozzleorifice 14 is provided with an outer beveled valve seat 59 adapted toseat the corresponding beveled surface 60 of exit valve 30. When suchvalve is only slightly opened as shown in Fig. 8, the swirling uid isdischarged through the orifice at an angle determined by such parallelspaced seat portions 59 and 6i). By providing a more obtuse conicalcontour (i. e. of greater vertex angle) to the inner beveled surface 61,the angle of the spray envelope will be determined by whichever surface60, 61 is more nearly juxtaposed to seat 59. Consequently, as indicatedin Fig. 9, when the valve is relatively widely opened with a large fuel-llow passing through the nozzle orifice, the angle of the conical sprayenvelope is relatively wide near its apex, thereby counterbalancing thetendency to form a rounded shape and maintaining the desired anglewithin prescribed limits. A succession of more than two such conicalsurfaces of increasingvertex angles may be provided, or a continuouscurved surface may be utilized to obtain somewhat the same effect. Igenerally prefer, however, to utilize an intervening cylindrical surfaceas shown in Figs. 247 inclusive between the two conical surfaces inorder to ensure a definite transition from one spray cone angle toanother when such is desired. Without such marked interruption in thepoppet valve surface opposed to the exit orice 14, the swirling actionof the fluid (e. g. jet engine fuel) tends to cause the same to cling tothe valve member so that the outer conical surface maintains anundesired influence on the spray cone even when the valve is quitewidely opened.

It will, of course, be noted that when the exit valve member isreciprocated from slightly open to fully open position -the twodifferent conical surfaces thereon are sequentially opposed to the outeredge of the exit oriiice 14. Such orifice will ordinarily be ofcylindrical conformation and of relatively short longitudinal extentcompared to the sum of the two conical surfaces of the valve member andthe usual intervening land. Itis the cooperative effect of suchon'tlceand the adjacent portion of the valve member which determines theshape of the spray cone or sheaf at different rates of flow. As aboveindicated, the exit valve member automatically moves further outwardlyas the rate of flow increases. The swirling movement of the uid aboutthe constricted valve stem due to the helical inlet passages leading tothe swirl chamber immediately upstream of the orifice causes such uid tofollow the contour of the valve member as it passes through the annularopening and thereby to assume the desired conical form as well asassisting in the ultimate separation of the fluid into minute droplets.

The cylindrical lands intermediate and spacing the conical surfaceportions of the tappet exit valve member aiord the desired transitionwithout such a break in the fluid ow as might cause uncontrolledturbulence. The fluid flow enters the swirl chamber 26 through aplurality of angularly arranged inlet passages (helical passages 29 nand tangential inlets 25) and is wrapped around valve stem 51. Theportion of the valve member juxtaposed to the outer edge of exit orice14 substantially determines the form of the spray cone delivered.

The. spray cone angle and desired changes therein at different rates offlow are specified for best results for use in different designs of jetengine burners, for example, and my exit valve construction makespossible the accurate control desired. When conical surfaces 55 and S6(Fig. 6) are of the same vertex angle it will nevertheless be seen suchsurfaces are axially offset and the break formed by land 57 helpsprevent the swirling liquid in circular swirl chamber 26 from continuingto cling to the surface beyond the end of portion 57 when the valve iswidely opened. The Figs. 8 and 9 arrangement is relatively inexpensiveand has been found satisfactory for large capacity nozzles. Ordinarily,however, the employment of a step, break, or land intermediate theconical surfaces is much preferred for the reasons indicated.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, Yprovided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a nozzle having an exit orifice and an axially reciprocable tappetvalve member adapted to seat in such orifice, a primary conical portionon said member adapted to seat against the outer edge of such orificewhen the valve is closed and to determine ythe initial angle of thespray cone delivered by such nozzle when such valve is opened, and asecondary conical portion on said member upstream of said primaryconical portion and having a smaller vertex angle than said primaryconical portion, said secondary conicalportion being adapted to be juxtaposed to such outer edge of such orifice when the valve is more widelyopened and then to determine such spray cone angle, the vertices of bothsuch cones lying upstream of said primary conical portion, and saidupstream secondary conical portion being axially spaced from saidprimary conical portion a sufficient distance to ensure that such spraycone determined thereby will clear said Aprimary conical portion despitethe greater vertex angle of the latter.

2. In a nozzle having an exit orifice and an axially reciprocable tappetvalve member adapted to seat in Vsuch orifice, a primary conical portionon said member adapted to seat against the outer edge defining suchorifice when the valve is closed and to Idetermine the initial angle ofthe spray cone delivered by such nozzle when such valve is opened, asecondary conical portion on said member upstream or" said primaryconical portion adapted Vto be juxtaposed to such outer `edge of suchoriiice when the valve is more widely opened and `then to determine`such spray cone angle, the vertices of both such cones lying upstreamof said primary conical portion and pointing in the same direction withthe projected surface of said secondary conical portion completelyclearing the surface of said primary conical portion, and a cylindricalland intermediate said conical portions directly joining the same, withthe smaller end surface of said primary conical portion terminating atone margin of said land and the larger end surface of said secondaryconical portion'terminating at the other margin of said land.

3. In a nozzle having an exit orifice and an axially reeiprocable tappetvalve member adapted to seat in such orifice, a primary conical portionon said member adapted to seat against the outer edge defining Vsuchorifice when the valve is closed and to determine the initial angle ofthe spray cone :delivered by such nozzle'when such valve is opened, asecondary conical portion on said member upstream of said prima-ryconical portion adapted to be juxtaposed to such outer edge of suchorice when the valve is more widely opened and then to determine suchspray cone angle, the vertices of both such cones lying upstream of saidprimary conical portion and pointing in the same direction with theprojectedsurface of said secondary conical portion completely clearingthc surface of said primary conical portion, and a land intermediate andspacing said conical portions directly joining the same, with thesmaller end surface of said primary conical portion terminating atone'margin of said land and the larger end surface of said secondaryconical portion terminating at the other margin of said land.

4. In a nozzle having an exit orifice and an axially reciprocable tappetvalve member adapted to seat in such orifice, a primary conical portionon said member adapted to seat against the outer edge of such orificewhen the valve is closed and to determine the initial angle of the spraycone delivered by such nozzle when such valve is opened, a secondaryconical portion on said member upstream of said primary conical portionadapted to be juxtaposed to such outer edge of such orifice when thevalve is more widely opened and then to determine such spray ,cone

angle, the vertices'of both such cones lying Vupstream of vsaid .primary:conical `portion and pointing in the same direction, .the projectedsurface of said seconda-ry conical vportion .completely clearing thesurface of said primary conical portion, a land inteimediate and spacingsaid conical portions directly joiningthe same, with the smaller endsurface of said primary conical portion term-inating at one margin .ofsaidland and the larger end surface .of said secondary conical portionterminating at the other margin of said land, a swirl chamberimmediately upstream of such exit orifice through Which the stem of suchtappet valve member passes, and a plurality of angularly disposed fluidinlet passages leading into said swirl chamber adapted to deliver aswirlingiluid llovv about such stem.

5. In a nozzle having a cylindrical exit orifice kand an axiallyreciprocable tappet valve member adapted to seat in such orifice, `aprimary concalzpo-rtion on said member adapted to seat against the outeredge of such orifice when the valve lis closed and to 'determine theinitial angle of the spray cone delivered `by such nozzle when suchvalve is opened, a secondary conical portion` on said member upstream ofsafd lprimary conical yportion adapted to ybe juxtaposed to such outeredge ,of such orifice when the vvalve is more Widely opened and then todetermine such spray cone angle, the vertices `of both such cones lyingupstreamof Vsaid primary conical portion and pointinng inthe samedirection, the projected surface of said secondary conical portioncompletely clearing the surface ,of said primary conical portion, acylindrical land'intermediate said conical portions 'directly joiningthe same, with the smaller end surface of said primary conical portionterminating 'at-one margin of said land and the larger end surface ofsaid secondary conical portion terminating at -th'e other margin -ofsaid land, a swirl chamber immediatelyfupstreamof lsuch exit oricethrough which the stem of such tappet valve member passes, and aplurality ofangularlydisposed:iluid inlet passages leading into saidkswirlchamber adapted to deliver a Vswirling fluid flow about. suchstem.

6, `In a nozzle having an exit oriice and an axially reciprocable tappetvalve member adapted to seat in such orifice, twoaxially spaced conicalportions on saidmember adapted selectively to ,determine the angle ofthe spray cone delivered by such nozzle from such orifice, said conicalportions being directly connected by a cylindrical land, with thesmaller end surface of said` primary conical portion terminating at onemargin of said land and the larger end surface of said secondary conicalportion terminating atthe other margin of said land, the vertices of.both such cones-pointing upstream witth the projected surface of saidsecondary conical portion completely clearing .the surface of saidprimary conical portion, a swirl cham- `ber upstream of :such exitorifice through which the stem of such tappet valve member passes,circumferential tangcntially disposed fluid inlets to said chamber, andseparate angularly inclined fluid Ainlets tothe end of said .chamberkopposite Vthe ,end having such exit orifice, to deliver .a swirlingfluid flow about such stem travelling out through such orifice.

References Cited in the le of this patent UNITED STATES PATENTS GermanyAug, 27, 19.30

